Olympus has never had a really fast-shooting digital system camera. There was the E-100 RS back in 2000, but that was a bridge camera and although it could shoot at up to 15 frames per second, maximum resolution was just 1.4 megapixels. Until the E-M5 came out the fastest you could get with an Olympus Four Thirds camera was 5 frames per second with the E-3 and, later, the E-5. The Pen E-PL3 and E-PM1 can shoot at just under 5 fps. On paper, the E-M5 is a much more exciting 9 fps. Our timings indicate the E-M5 is more like a 10 fps shooter.

Our E-M5 was set to record Super Fine Large JPEGs and RAW files simultaneously and Image stabilisation was set to Mode 1. We used four different types of card; a Lexar Pro 600X UHS-1, Kingston Ultimate XX 233X UHS-1, Panasonic Gold Class 10, and a SanDisk Extreme Pro UHS-1 (45MB/sec rated - 300x approx, not the 95MB top-spec version of this card), and measured the frame rate and recovery times for each using High Speed shooting mode. Focus was set to manual although single shot AF should deliver similar results.

All four cards produced bursts of 11 or 12 frames at a rate of approximately 10fps, roughly 1.2 seconds of full-speed continuous shooting. This is interesting because Olympus' official specifications only claim 11 frames at 9fps shooting RAW. Olympus also told us that IS would slow the shooting rate down, which it clearly didn't. Curiously, two of the higher-specification cards, the Lexar Pro and Kingston XX Ultimate, although they shot 12 frames in the sequence, the last frame took twice as long to register as the previous one, so we excluded it, only counting the 11.

After the buffer stalls the screen freezes for a few seconds - 6-7 seconds depending on the card. The Lexar Pro emptied the buffer in 20 seconds while all the other cards took much longer - between 30 and 34 seconds. Although three if the cards we tested were UHS-1 types, only the Lexar Pro seemed to offer any benefit in the camera, although UHS-1 does offer higher speeds in compatible card readers.

So the conclusion is, if you can afford the extra cost of a Lexar Pro 600X card for you E-M5, you will wait significantly less time for the camera buffer to be cleared and your camera will become responsive again much sooner.